BoilerFaultCodesYour boiler is struggling to maintain a steady fan speed, which is preventing it from completing its startup sequence and heating your home.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Replace printed circuit board.
What causes this fault?
This fault occurs when the boiler's control centre is no longer able to send a consistent voltage to the fan, causing it to speed up and slow down erratically. The most common reason is that the electrical components on the main circuit board have aged and degraded, losing their ability to regulate the startup sequence correctly.
This issue often becomes apparent during the first cold spell of autumn, when the circuit board is suddenly tasked with constant operation after being idle over the summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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